How may high mileage impact a vehicle's emission systems?

High mileage can significantly impact a vehicle's emission systems primarily due to the wear and tear that occurs over time. As a vehicle ages and accumulates mileage, certain components such as the engine, exhaust system, and emission control devices may deteriorate or malfunction. For example, worn piston rings can lead to increased oil consumption, while a failing catalytic converter can fail to adequately convert harmful emissions into less harmful substances.

This deterioration can result in higher levels of pollutants being emitted from the vehicle, as the systems designed to reduce emissions become less effective. Additionally, older vehicles are likely to have outdated technologies that do not meet current emission standards, which can further exacerbate the issue. Therefore, high mileage not only correlates with physical degradation of parts but also increases the likelihood of emission-related failures, making this answer the most accurate in the context of how high mileage affects emission systems in vehicles.